Abrasive tool.



J. R. THOMAS.

ABBABIVE TOOL.

Patented Dec. 19, 1911.

J50 R. 77/0/14 AS for 1o JOHN R. THOMAS, OF WILKES-BAKER, PENNSYLVANIA.

Y ABBASIVE TOOL.

Specification of Letters Patent. Application med September as, 1911'.

Patented Dec. 19I191'1'. Serial N0. 651,417.

To all whom it may concern:

Be it known that I, JOHN R. THOMAS, a citizen of the United States, residing at 'Wilkes-Barre, in the county of Luzerne and State of Pennsylvania, have invented a new and useful Im rovement in Abrasive Tools, of which the Following is a specification.

M invention relates to blocks or clamps olding abrasive fabric, such as emery cloth, sand aper and the like, the blocks beof sucl i size and formation as to form a %land tool for smoothing and polishing operations.

section of standard size sandpaper;

Referring to the drawings, Figure 1 is a erspective view of my improved .blocks; ig. 2 is an end elevation of the same; Fig. 3 1s a plan view of the lower block, and Fig. 4 is a sectional front elevation.

s shown, the toolis made in two arts, and its rectangular dimensions are suc that it is adapted to seat and clamp a quarp elp e lower block 10 is rovided with a cork layer 12 to form a resilient backing for the paper. The topsurface of the block is hollowed out longitudinally and is formed preferably of two reentrant an les 13, 18 with an intermediate flat, as shown in Fi 2. A transverse plate 15 provided wit notch 16.is located centrally upon the upper surface of the block, the angular parts 13, 13.being cut away to bed the plate 15 firmly upon the intermediate flat. A cavit 17 is located in the block in registration wlth the slot 16, as shown in Fig, 3.

The upper block 11 has its lower surface shaped to correspond with or match the lower block, and is fitted with a artly countersunk thumb-screw 14. The thumbscrew is provided with a left-hand thread 19 which engages a nu't late 22 fastened to the block 11. Below t e threaded ortion of the thumb-screw is a small shan terminating in a head 21. The abrasive fabric 18, as shown in Fig. 2 is clamped between the blocks 10 and 11.

To clam the blocks together, all that is necessary 1s to place the two together so that the head'21 of block 11 is in the cavity 17 of block 10. The blocks are then slid longitudinally upon each other until the shank 20 enters the slot 16.- A quarter turn of the thumb screw to the right 1s then suflicient to clamp the blocks rigidly together with the fabric gripped between them,

It will be noticed that'the arrangement ofparts is such that the entire rectangular bottom of the lower block may be completely covered with the sandpaper or emery cloth and that there are no projections on either the sides or the top of the blocks which extend .be ond the fabric when it is clamped in position. This feature is of great value in allowing the block to be used 1n corners and it enables the tool to be used efi'ectively on shouldered work and in many other cases where a block with projecting parts could not be used.

made without departin from the spirit of my invention, as the su stitution of felt'or fications of the clampmg device, so that I do not restrict myself to the particular arrangements of parts as shown and described.

I claim: 3

1. In combination, a pair of matched blocks for clamping abrasive fabric, one of said blocks having its lower surface faced with resilient material to serve as a backing -for the clamped fabric, and its upper surface of an approximately concave form, a locking plate mounted on the block, and

proximately convex form to match the uper surface of the first block and a screw olt passing through said second block and adapted to enga e the saidlocking plate to clamp the two b ocks together, substantially as described.

2. In combination, a pair of matched blocks for clamping abrasive fabric, one of said blocks-being rovided with the plate 22 having a three ed aperture, a bolt having a threaded portion 19 engaging the plate 22, a shank 20, and a head 21, the said head 21 being of a smaller diameter than the internal diameter of said aperture so,

and means carried by the second block adapted to coiiperate with said bolt to lock the two blocks together, substantially as shown and described.

3. In combination, a pair of matched blocks for clamping abrasive fabric, the block 11, being provided with a plate 22, a thumb-screw 14 having an intermediate threaded portion 19 engaging said plate, and having a reduced shank 20, and a head 21, the head being of lesser diameter than the threaded portion 19 measured at the bottom of the thread, the said thread being the second block, having one surface of ap-.

that said bolt and plate may be separated,

It is obvious that many changes may be I rubber for the cork layer, and minor modileft-handed, and the blocl: 10 carrying the notched plate 15 adapted to coii rate with the thumb-screw 14, substanti y .as described. I

4. In combination, a pair of matched blocks for clamping abraslve fabric,-one of said blocks havmg reentrant angles 13, 13, the second block havin angles thereto, one of sai blocks having a 10 notched plate, the other block having a bolt complementary adapted to enter the said-notch and engage the plate, the arrangement being such that the blocks may be completely separated from each other, substantially as shown and described.

- JOHN R. THOMAS."

Witnesses v Romm'r MAGRANE,

A. L. TURNER. 

